Integrated process condition sensing wafer and data analysis system

ABSTRACT

A process condition measuring device and a handling system may be highly integrated with a production environment where the dimensions of the process condition measuring device are close to those of a production substrate and the handling system is similar to a substrate carrier used for production substrates. Process conditions may be measured with little disturbance to the production environment. Data may be transferred from a process condition measuring device to a user with little or no human intervention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 60/430,858 filed on Dec. 3, 2002; U.S. ProvisionalPatent Application No. 60/496,294 filed on Aug. 19, 2003; U.S.Provisional Patent Application No. 60/512,243 filed on Oct. 17, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to semiconductor wafer processing, LCDdisplay glass substrate processing, magnetic memory disc processing, andother devices fabricated from thin film processes, and, morespecifically, to a system that can sense and record processingconditions and transmit data to a receiver.

2. Discussion of the Related Art

The fabrication of an integrated circuit, display or disc memorygenerally employs numerous processing steps. Each process step must becarefully monitored in order to provide an operational device.Throughout the imaging process, deposition and growth process, etchingand masking process, etc., it is critical, for example, thattemperature, gas flow, vacuum, pressure, chemical, gas or plasmacomposition and exposure distance be carefully controlled during eachstep. Careful attention to the various processing conditions involved ineach step is a requirement of optimal semiconductor or thin filmprocesses. Any deviation from optimal processing conditions may causethe ensuing integrated circuit or device to perform at a substandardlevel or, worse yet, fail completely.

Within a processing chamber, processing conditions vary. The variationsin processing conditions such as temperature, gas flow rate and/or gascomposition greatly affect the formation and, thus, the performance ofthe integrated circuit. Using a substrate to measure the processingconditions that is of the same or similar material as the integratedcircuit or other device provides the most accurate measure of theconditions because the material properties of the substrate is the sameas the actual circuits that will be processed. Gradients and variationsexist throughout the chamber for virtually all process conditions. Thesegradients, therefore, also exist across the surface of a substrate, aswell as below and above it. In order to precisely control processingconditions at the wafer, it is critical that measurements be taken uponthe wafer and the readings be available in real time to an automatedcontrol system or operator so that the optimization of the chamberprocessing conditions can be readily achieved. Processing conditionsinclude any parameter used to control semiconductor or other devicefabrication or any condition a manufacturer would desire to monitor.

Within the processing chamber a robot transports the test wafer orsubstrate. One example of a device incorporating a robot is manufacturedby the TEL Corporation. For more information about the robot andprocessing chamber, please refer to U.S. Pat. No. 5,564,889 to Araki,entitled “Semiconductor Treatment System and Method for Exchanging andTreating Substrate,” which is hereby incorporated by this reference inits entirety. This application relates to U.S. Provisional PatentApplication No. 60/430,858 filed on Dec. 3, 2002; U.S. ProvisionalPatent Application No. 60/496,294 filed on Aug. 19, 2003; U.S.Provisional Patent Application No. 60/512,243 entitled “IntegratedProcess Condition Sensing Wafer and Data Analysis System” by Wane Renkenet al, filed on Oct. 17, 2003; and to U.S. patent application Ser. No.10/056,906 to Renken, which are hereby incorporated by this reference intheir entirety.

SUMMARY OF THE INVENTION

A process condition measuring device (PCMD) is disclosed that may bedelivered to a target environment, acquire a wide range of data andreturn to a handling system with little disruption to the targetenvironment or the tool containing the target environment. The PCMD isdesigned to have similar characteristics to the substrates normallyhandled by the tool. The characteristics of such substrates aregenerally specified by industry standards. Thus, for a system designedfor 300 mm silicon wafers, the PCMD-has a silicon substrate and hassimilar physical dimensions to those of a 300 mm wafer. Components maybe located within cavities in the substrate to keep the profile of thePCMD the same as, or close to that of a 300 mm wafer. Because of itsdimensions and its wireless design, the PCMD may be handled by a robotas if it were a 300 mm wafer. It may undergo the process steps undergoneby wafers such as etch, clean, photolithography etc. The PCMD recordsprocess conditions such as temperature, pressure and gas flow rateduring processing and uploads the data when requested. Conditions duringtransport and storage may also be monitored and recorded.

Making a PCMD employs multiple process steps similar to those used insemiconductor IC manufacturing. An insulating layer is deposited overthe substrate. A conductive layer is deposited and patterned to formtraces. Cavities are formed in the substrate surface and components areplaced in those cavities. Components are then bonded to traces to formelectrical connections. A passivation layer may then be deposited overthe surface to protect the substrate, components and the wire bonds.

PCMDs may be made compatible with harsh environments by protectingcomponents from chemical or electrical damage. Critical components mayhave covers similar to parts used in packaging ICs. Covers may also bemade of specialized materials such as sapphire or, for electricalprotection, silicon or metal. PCMDs may also be adapted to hightemperatures by incorporating a temperature compensating circuit toallow an oscillator to perform outside its specified temperature range.

A handling system provides a base for a PCMD. The PCMD exchanges datawith an electronics module when it is docked in the handling system andalso receives power from the electronics module. The handling system maycomprise an electronics module within a standard substrate carrier suchas a front opening unified pod (FOUP). This allows the handling systemto be highly integrated with a tool or with facility automation. ThePCMD may be moved to and from the FOUP by the tool and the FOUP may bemoved from one tool to another by the facility automation. The FOUPprovides a clean environment for the PCMD where it may be stored ortransported. In addition, loading stations for FOUPs are normallyprovided with RFID readers to determine the identity of the FOUP andrelay the information to a tracking system via a network. By connectingthe electronics module in the FOUP to an RFID transceiver, data from theelectronics module may be sent to the network where it may be accessed.

A handling system may have an alignment module that may move a PCMDwithin a handling system. Vertical and rotational motion of a PCMD maybe achieved by a rotation stage or wheels supporting its perimeter.Raising a PCMD may allow better coupling to the electronics module.Lateral movement of the PCMD may be achieved by a moving belt or wheelthat is brought into contact with the lower surface of the PCMD to movethe PCMD into position.

A PCMD may have a pattern on its surface that allows its orientation tobe determined. Greycode printed on the edge, of a surface of a PCMD mayallow the rotational orientation of the PCMD to be determined. Greycodereaders may be installed in a handling system so that the orientation ofthe PCMD is known before it is sent on a survey and after it returns.Such a system does not require movement of the PCMD relative to thereaders in order to determine orientation.

A PCMD may have temperature compensation circuitry to allow componentsto operate at high temperatures. An oscillator within a clock circuitmay have its bias adjusted as the temperature changes so that theoscillator continues to function beyond its specified temperature range.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a plan view of Process Condition Measuring Device (“PCMD”)100.

FIG. 1B is a depiction of components within PCMD 100.

FIG. 1C is a cross section of a single component within PCMD 100.

FIG. 1D is a plan view of an embodiment of PCMD 100 with graycodecoding.

FIG. 1E shows PCMD 100 spinning about a central axis 199.

FIG. 2A is a perspective view of the back of Handling System (“HS”) 200.

FIG. 2B is a perspective view of the front of HS 200.

FIG. 2C is a processing tool 260 having a robot that transferssubstrates between a substrate carrier and a processing chamber.

FIG. 2D is a cross-sectional view of processing tool 260.

FIG. 3A is a cross section of an embodiment of PCMD 100.

FIG. 3B is a cross section of another embodiment of PCMD 100.

FIG. 4A is a flowchart depicting the steps of making the cross sectionshown in FIG. 3A.

FIG. 4B is a flowchart depicting the steps of making the cross sectionshown in FIG. 4A.

FIG. 5A is a cross-section of an E-coil 510 inductively charging a coil508.

FIG. 5B is a cross-section of an E-coil 510 inductively charging a coil508 with a magnetic conductive layer 555.

FIG. 6 is a circuit diagram of a high temperature crystal oscillatorcircuit 660.

FIG. 7 shows a PCMD 700 having-four transmitters 728-731.

FIG. 8A shows a handling system 880

FIG. 8B shows a portion of a PCMD having greycode 850.

FIG. 8C shows an alignment module 881.

FIG. 8D shows handling system 880 with PCMD 800 in the normal position.

FIG. 8E shows handling system 880 with PCMD 800 in the raised position.

FIG. 8F shows alignment module 881 with PCMD 800.

FIG. 8G shows alignment module 881 moving PCMD 800 laterally.

FIG. 8H shows alignment module 881 raising and rotating PCMD 800.

FIG. 8I shows E-coil 810 moving vertically towards PCMD 800.

FIG. 9 shows various communication systems between PCMD 900, handlingsystem 980 and software application 987.

FIG. 10 shows different examples of lids protecting components of PCMDs.

DETAILED DESCRIPTION

The measurement system in one embodiment measures processing conditionsin various locations of a wafer or substrate and records them in memoryfor later transmission or downloading of the process conditions. Inanother embodiment of the measurement system where a processing chamberhas windows capable of data transmission, the system is additionallycapable of transmitting the processing conditions in real time to a dataprocessing device.

FIG. 1A illustrates process condition measuring device (“PCMD”) 100, anembodiment of the present invention. PCMD 100 is part of a processmeasurement system, the other components of which will be describedlater with reference to FIGS. 2. PCMD 100 comprises a substrate such asa silicon wafer, glass substrate, or other substrates well known in theart. Substrate 102 (not visible in plan view) is preferably a siliconwafer and may be of any diameter but is preferably an 8, 10, or 12 inchdiameter wafer.

A number of components are integrated to form PCMD 100. Sensors 124 aredistributed about PCMD 100 and are, therefore, capable of detectinggradients in various processing conditions across the surface of thesubstrate. Sensors 124 are connected to the microprocessor 104 throughconductive traces 120. Conductive traces 120 preferably comprisealuminum, but may comprise any conductive material, the formation ofPCMD 100, including the conductive traces and the other components willbe described later with reference to FIGS. 3 and 4. Microprocessor 104preferably includes flash memory cells for storing the processingconditions and other instructions necessary for the operation of PCMD100. However, the flash, or other type memory, may alternatively be partof a discrete EPROM or EEPROM rather than being an integral part ofmicroprocessor 104. Clock crystal 132 generates a timing signal used invarious operations of PCMD 100. Transmitter 128 preferably comprises alight emitting diode (LED) for transmitting data. Around transmitter 108is a radio frequency (RF) inductive coil 108 that receives data andserves to inductively charge power sources 112A and 112B. In oneembodiment of the invention, transmitter 128 may also act as atransceiver and receive data as well as transmit data. Additionally,coil 108 may also act not only as a receiver, but also as a transmitter.Thus, coil 108 may serve as a receiving unit that may receive both dataand power.

In the embodiment illustrated, power sources 112A and 112B are thin filmlithium ion batteries that are equidistant from the center of the PCMD100. The thin 0.25 mm thick power sources allow for a thin overall PCMDstructure with a thickness of 0.70 mm, which is comparable to aproduction wafer and compatible with the robot arms typically used inwafer handling procedures. These power sources have previously beencommon to under-skin medical implants where they are similarlyinductively charged. Power sources 112A and 112B are capable ofcontinuous operation at temperatures up to roughly the melting point oflithium, around 180 degrees Centigrade. The equidistant spacing of thepower sources 112A, 112B shown in FIGS. 1D and 1E, maintains the balanceof PCMD 100 which is beneficial in situations where PCMD 100 may bespinning within a processing module. FIG. 1E shows the central axis 199of PCMD 100 passing through the center of PCMD 100. Central axis 199 isperpendicular to a surface 198 of PCMD 100. The center of gravity ofPCMD 100 lies along central axis 199. Central axis 199 is the axis ofrotation when PCMD is spun in a processing module. Batteries 112A and112B are equidistant from central axis 199 and are 180 degrees apart.Thus, where batteries 112A and 112B are of the same mass, their combinedcenter of gravity is along central axis 199. Additionally, the othercomponents are arranged in order to maintain as uniform a mass andthermal profile as possible. A passivation layer 116 and an optionalshield layer are formed above all of the components of PCMD 100 in orderto protect the components and substrate from various processingconditions. The layers that make up PCMD 100 will be described infurther detail later with reference to FIGS. 3 and 4.

Coil 108 of FIG. 1 may be located within a cavity in the substrate. Coil108 may be extremely thin so that it does not add to the overall heightof the PCMD 100. For example, FIG. 5A shows a cross-section of a coil508 during inductive charging. In this example, coil 508 includesseveral windings of increasing radius. However, coil 508 is only onewinding in height so that the thickness of coil 508 is approximately thesame as the thickness of the conductor used for the winding. Coil 508may be located in the middle of the wafer as shown in FIG. 1A. FIG. 5Ashows a similar coil 508 in a cavity 550 within the substrate 502. FIG.5A shows the position of coil 508 with respect to an E-coil 510 locatedin electronics module 508. E-coil 510 may be used to supply power to thePCMD 100 by inducing an electrical current in the windings of coil 508.E-coil 510 may also be used to transmit data to coil 508. Thus, theinduced field is used to transmit both power and data to PCMD 100.E-coil 510 typically provides an RF field at a frequency of 13.56 MHz.One advantage of placing coil 508 so that its axis passes through thecenter of the PCMD is that it may easily be aligned with an externalunit such as E-coil 510 because the rotational orientation of PCMD 100does not affect the position of the coil 508. Thus, E-coil 510 may serveas a transmitting unit that may transmit both power and data.

FIG. 5B shows coil 508 having a magnetic conductive layer 555. Magneticconductive layer 555 may be made of a ferrite material. The inducedfield is concentrated in magnetic conductive layer 555 and so themagnetic field in the substrate 502 is minimized. Where the substrate502 is made of a conductive material such as doped silicon this isespecially advantageous. When the RF field extends into a conductivesubstrate the changing magnetic field in the substrate induces eddycurrents. These eddy currents dissipate the RF field and result in alower efficiency of power transfer between E-coil 510 and coil 508. Inaddition, eddy currents flowing through a conductive substrate may heatthe substrate and could damage PCMD 100.

Clock crystal 132 is part of a crystal oscillator circuit. FIG. 6 showsan example of a high temperature crystal oscillator circuit 660 that maybe used for this application. High temperature crystal oscillatorcircuit 660 is comprised of a conventional crystal oscillator circuit661 and a biasing circuit 670. The conventional oscillator circuit 661includes a crystal 632, amplifier 662 and capacitors 663 and 664. Theamplifier 662 and capacitors 663 and 664 are within CPU 604, while thecrystal 632 is external to the CPU. The biasing circuit 670 includescounter 671, ring oscillator 672 and bias control unit 673 within CPU604. In addition, biasing circuit 670 includes a series of resistors 675that are connectable to the crystal under the control of bias controlunit 673. Resistors 675 are external to CPU 604.

Amplifier 662 provides positive feedback to maintain the oscillatorsignal. Amplifiers available in commercially produced ICs, such asamplifier 662, are specified as working over a certain range oftemperature, for example 0-85 degrees centigrade. When the temperatureis higher than the specified range, conventional oscillator circuit 661may no longer function correctly. Threshold voltages of components inthe amplifier may shift which eventually causes oscillation to, cease orstartup to fail. When amplifier 662 is working within its specifiedtemperature range it produces a signal with a 50% duty cycle. Withincreasing temperature the duty cycle increases and as the duty cycleapproaches 100% conventional oscillator circuit 661 ceases to function.

Biasing circuit 670 overcomes this problem by biasing the input ofamplifier 662 in order to maintain a 50% duty cycle. Counter 671 usesthe input from ring oscillator 672 to determine the duty cycle. Counter671 counts the number of clock cycles of ring oscillator 672 during the“on” phase of the output of amplifier 662. It then counts the number ofclock cycles of ring oscillator 672 during the “off” phase of the outputof amplifier 662. The counts are sent to the bias control unit 673 wherethe duty cycle is determined. If these counts are equal then the dutycycle is 50%. If the count for the “on” phase exceeds the count for the“off” phase, then the duty cycle is greater than 50%. The frequency ofring oscillator 672 is greater than the frequency of the output ofconventional oscillator circuit 661. Typically, the conventionaloscillator circuit has an output frequency of about 32 kHz while thering oscillator has an output frequency of about 400 kHz-4 MHz. Ringoscillator 672 may suffer from a change in frequency at hightemperature. However, because the output for two periods are compared,the absolute value of the output over a given period does not affect thedetermination of duty cycle.

If the duty cycle is determined to be greater than 50% the bias controlunit 673 may modify the bias input 676 to reduce the duty cycle. Thismay be done in a number of ways. In the example shown in FIG. 6, aseries of resistors 675 of different resistances are connected between abias voltage and bias input 676. The bias voltage used may be Vcc on theCPU chip. In this way, the voltage and current at the input of amplifier662 may be controlled to bring the duty cycle back to; 50%. Using thistechnique, the effective range of high temperature crystal oscillatorcircuit 660 may be extended from the stated upper limit of the CPU chip604 (85 degrees centigrade) to as high as 150 degrees centigrade. Thisallows PCMD 100 to use standard parts in conditions that would otherwiserequire custom parts. As alternatives to using resistors 675, othercomparable means may be used to modify impedance such that a change inbias is achieved. These alternatives include an electronicpotentiometer, transistor, voltage resistor network.

Transmitter 128 shown in FIG. 1A may be used to transmit data from thePCMD. Here, transmitter 128 is an LED. This is a more energy efficientway to transmit data than using RF via coil 108. For transmission fromthe PCMD energy efficiency is important, whereas for transmitting datato the PCMD energy is generally not as critical so that RF may be used.In-the example shown in FIG. 1A the transmitter is located at the centerof the upper surface of the PCMD. Placing LED 128 in the center allowsit to be more easily aligned with any external receiver because theposition of LED 128 with respect to the external receiver will not varyif PCMD 100 is rotated. This may be important where PCMD 100 is rotatedduring a survey as occurs in some environments.

In another embodiment shown in FIG. 7, four transmitters 728-731 arelocated around coil 708. This example also uses LEDs as transmitters728-731. Using multiple LEDs allows a receiving unit 777 in anelectronics module 778 to receive a good signal even where receivingunit 777 is not aligned with the center of PCMD 700. Where one LED atthe center of a PCMD is used (as in FIG. 1) but the receiving unit inthe electronics module is offset from the center, a poor signal or nosignal may be received because the LED directs light in a limited cone.The receiving unit 777 may be offset because the E-coil occupies a spacecovering the center of the PCMD. Thus, it is desirable to have one ofLEDs 728-731 aligned with the offset position of the receiving unit 777.This requires more than one LED (four, in this example) so that one LEDis below the receiving unit regardless of the rotational orientation ofthe PCMD 700. However, for energy efficiency it is desirable to transmitvia only one LED. Therefore, a technique is provided for determining theoptimum LED to transmit data.

The optimum LED is determined as part of a hand-shaking routine betweenthe electronics module 708 and the PCMD 700. First, the electronicsmodule 708 sends a signal to the PCMD 700 via the RF coil 708, tellingPCMD 700 to begin transmission. The PCMD 700 begins transmitting usingLED 728. If the electronics module 708 does not receive a signal after apredetermined time, another signal is sent to the PCMD 700 requesting atransmission. The PCMD 700 transmits using LED 729. If receiving unit777 receives no signal, then LED 730 is used. If no signal is receivedfrom LED 730, then 731 is used. Because LED 731 is directly belowreceiving unit 777, the signal is received and LED 731 is identified asthe optimum LED The PCMD then uses only the optimum LED 73 land may turnoff the other LEDs 728-730 to conserve energy. More LEDs may be useddepending on the configuration of the receiving unit or units. LEDsmaybe arrayed in different locations and pointed in different directionsdepending on where the data is to be sent.

Utilizing the limited storage capacity of the power sources efficientlyis desirable to maximize the amount of data and measurement time of thePCMD. The sensor groups that are activated are user selectable, thegroups are only activated when necessary. Outputs from selected groupsare multiplexed and only written into memory at-selected intervals. Theoutput is also compressed to minimize the amount of time and energyneeded to store the data.

As defined herein, “processing conditions” refer to various processingparameters used in manufacturing an integrated circuit. Processingconditions include any parameter used to control semiconductormanufacture or any condition a manufacturer would desire to monitor suchas, but not limited to, temperature, processing chamber pressure, gasflow rate within the chamber, gaseous chemical composition within thechamber, position within a chamber, ion current density, ion currentenergy, light energy density, and vibration and acceleration of a waferor other substrate within a chamber or during movement to or from achamber. Different processes will inevitably be developed over theyears, and the processing conditions will, therefore, vary over time.Therefore, whatever the conditions may be, it is foreseen that theembodiments described will be able to measure such conditions.

Sensors 124 are used for detecting various processing conditions aremounted on or fabricated in substrate 102 according to a well-knownsemiconductor transducer design. For measuring temperature, a populartransducer is an RTD or thermistor, which includes a thin-film resistormaterial having a temperature coefficient. A magneto-resistive materialmay also be used to measure the temperature through the amount ofmagnetic flux exerted upon substrate 102. A resistance-to-voltageconverter is often formed within the substrate between distal ends ofthe resistive-sensitive material (either thermistor or magneto-resistivematerial) so that the voltage may easily be correlated with atemperature scale. Another exemplary temperature sensor includes athermocouple made of two dissimilar conductors lithographically formedin the layers of the substrate. When the junction between the conductorsis heated, a small thermoelectric voltage is produced which increasesapproximately linearly with junction temperature. Another example of atemperature sensor includes a diode that produces a voltage thatincreases with temperature. By connecting the diode between a positivesupply and a load resistor, current-to-voltage-conversion can beobtained from the load resistor. Another sensor is a piezoelectricdevice such as a quartz tuning fork fabricated from quartz crystal cuton a crystal orientation which exhibits a temperature dependentfrequency of oscillation. The sensor's oscillating frequency can bereferenced against a master oscillator formed by a piezoelectric devicesuch as a quartz tuning fork, which is fabricated from a crystaloriented to minimize frequency change with temperature. The frequencydifference between the sensor and master oscillator would provide adirect digital temperature dependent signal. Piezoelectric sensors mayalso be used to sense mass change to measure deposition mass and ratesor other process conditions.

Sensors 124 may also be used to measure pressure, force or strain atselect regions across substrate 102, either as a discrete sensor or asensor integrally formed in the layers of substrate 102. There are manytypes of pressure transducers capable of measuring the atmosphericpressure exerted upon the wafer. A suitable pressure transducer includesa diaphragm-type transducer, wherein a diaphragm or elastic elementsenses pressure and produces a corresponding strain or deflection whichcan then be read by a bridge circuit connected to the diaphragm orcavity behind the diaphragm. Another suitable pressure transducer mayinclude a piezoresistive material placed within the semiconductorsubstrate of substrate 102. The piezoresistive material is formed bydiffusing doping compounds into the substrate. The resultingpiezoresistive material produces output current proportional to theamount of pressure or strain exerted thereupon.

Sensors 124 may also be used to measure flow rate across substrate 102.In addition, humidity and moisture sensors can also be formed uponsubstrate 102. A well-known method for measuring flow rate, a hot-wireanemometer, may be incorporated into substrate 102. Fluid velocity isbased upon the frequency of vortex production as a streamlined fluidicflow strikes a non-streamlined obstacle positioned on or in substrate102. Measurement of fluid flow generally involves the formation ofspecial vortices on either side of the obstacle. Thus, an alternatingpressure difference occurs between the two sides. Above a threshold(below which no vortex production occurs), the frequency is proportionalto fluid velocity. Of many methods of detecting the alternating pressuredifference, a hot thermistor is preferably placed in a small channelbetween the two sides of the obstacle. The alternating directions offlow through the capitalized channel periodically cool the self-heatedthermistor thereby producing an AC signal and corresponding electricpulses at twice the vortex frequency. Therefore, an obstacle protrudingfrom substrate 102 in front of a thermistor can provide solid-state flowrate measurement. Heat can be transferred between self-heatedthermistors placed in close proximity to each other. Fluid flowtransfers thermal energy between the adjacent thermistors causing athermal imbalance proportional to mass flow. Two or more adjacentsensors can be arrayed to measure flow along a vector, or multiple flowvectors may also be sensed. The thermal imbalance can be detected toproduce a DC signal related to mass flow. Flows in multiple directionscan be compared to detect flow vectors.

Sensors 124 can also be used to measure the gaseous chemicalconcentration placed upon substrate 102. Chemical composition sensorsutilize a membrane which is permeable to specific ions to be measured.Ideally, the membrane should be completely impermeable to all otherions. The conductivity of the membrane is directly proportional to thetransport of select ions which have permeated the membrane. Given thevariability of membrane conductivity, measurements can be taken whichdirectly correlate to the amount of chemical ions present within theambient surrounding substrate 102.

Sensors 124 may also be used to measure ion current density and ioncurrent energy with a parallel plate structure, an array of collectingplates, and collecting plates with control grids supported above thecollecting plates. The current flowing between parallel plates, or tothe array of collecting plates will increase with ion current density.Ion current energy can be detected by applying a constant or varying DCpotential on the grids above the plates. This will modulate current flowwith ion current energy allowing the energy distribution to be detected.This is useful in monitoring and regulating a deposition or etchingprocess.

A piezoelectric transducer/sensor may also be integrated into substrate102 to measure the resonant frequency of a layer and thus the mass orthickness of the layer.

Additionally, sensors 124 can also be used to detect a change inposition or displacement of an object spaced from substrate 102.Exemplary displacement transducers include electro-optical devices whichcan measure photon energy (or intensity) and convert photon energy to anelectric field or voltage. Relatively well known electro-optical devicesinclude light-emitting diodes, photodiodes, phototransistors, etc.,which can be formed upon a semiconductor substrate or discrete devicesembedded within the substrate or placed on the surface. Displacementsensors are used to provide accurate information about electrode spacingwithin an etch or deposition chamber, and can also provide spacinginformation between a wafer and corresponding masks and/or radiationsource.

FIG. 1B illustrates some components of PCMD 100 within substrate 102.FIG. 1B is not a true cross section of PCMD 100, but only serves toillustrates how the components such as sensors 124, oscillator 132,microprocessor 104, power source 112, resistor 113, and capacitor 115are located within recesses formed in PCMD 100. Further details of thisare shown in FIG. 1C, where a component 140 is affixed to a cavity 142within substrate 102 (and the other layers on substrate 102) withbonding material 144. Bond wires 148 electrically couple the component140 with conductive traces 120 seen in FIG. 1A. Bond wires 148 andcomponent 140 are covered with potting material 152.

FIG. 1D illustrates an embodiment of PCMD 100 with graycode coding 150around the edge. This graycode coding is used to determine the positionor rotation of the PCMD with regard to reference axes, and will bedescribed in more detail later.

FIGS. 2A and 2B illustrate PCMD handling system (“HS”) 200. Handlingsystem 200 generally speaking includes a user interface and variouselectronic components, including a microprocessor and memory, fortransferring data to and from a number of PCMDs and for configuring,recharging, and transporting the PCMDs.

Cassette 204 can accommodate several PCMDs and may be located at anopening of a processing chamber or a tool that has multiple processchambers such that a robot arm may automatically place or remove thePCMDs within one of the various slots 250 of cassette 204. Cassette 204is a standard cassette that is compatible with a range of tools.Alternatively, a modified cassette could be used as long as it iscompatible with the mechanical automation used within the facility wherea PCMD is used. FIG. 2A illustrates the back or process side of HS 200.The PCMDs are inserted and removed from the process side. One PCMD 100is shown just below electronics module 208 and above charging board 216.When a PCMD is placed in the cassette, its power source(s) areinductively charged by electronics module 208 and charging board 216. Anadditional charging board may also be present in a push/pullconfiguration to increase the inductive charging rate. Although theembodiments described thus far utilize inductive charging, otherembodiments may utilize optical components for charging and datatransmission, although with the use of these optical componentsalignment is much more critical to proper recharging and datatransmission. In any embodiment, the PCMDs may include graycode codingaround the periphery, and HS 200 may also have optical sensors thatdetect the alignment of the PCMD while in the cassette 204 with thegraycode coding (FIG. 1D). Therefore, the wafer can be optimally alignedfor data recharging and data transmission. Additionally, if a PCMDreturns with a different alignment than it departed with, this mayindicate that it rotated some amount in the processing chamber, and thatthis rotation should be taken into account when analyzing the processingcondition data gathered from the chamber or other environment.

Substrates are typically stored and transported in a substrate carriersuch as cassette 204. Processing tools are adapted to a particularstandard substrate carrier. Typical tools have robots that movesubstrates from a substrate carrier through the tool and back to asubstrate carrier. Substrate carriers within a facility areinterchangeable so that the robot may be calibrated to a substratecarrier and continue to operate with similar substrate carriers withoutbeing recalibrated. A single substrate carrier standard is used so thata substrate carrier may be moved from one tool to another and the robotin each tool may transport substrates to and from the substrate-carrier.

FIG. 2C shows a view of a processing tool 260 that includes a robot 261that transfers substrates to a processing chamber 269. The robot has amechanical arm 262 with a blade (or endeffector) 263 attached to the endof arm 262 that can pick up a substrate 264. Substrate 264 is held in asubstrate carrier 265 so that the blade 263 may be extended undersubstrate 264 to pick up substrate 264. Blade 263 may rise to liftsubstrate 264 or substrate 264 may be lowered onto blade 263. Theposition of substrate 264 is important to allow blade 263 to pick upsubstrate 264. Typically a substrate carrier has multiple slots, eachslot holding one substrate. A slot is open on one side to allow asubstrate to be removed. A slot establishes the position of a substrate.In particular the height of a substrate above the bottom surface of thecassette is established to allow a substrate to be picked up. The bottomsurface of the cassette may be placed on a platform and the position ofa substrate above the platform is accurately established so that therobot may automatically pick it up.

FIG. 2D shows a side view of processing tool 260 showing blade 263extending under substrate 264 while substrate 264 is in substratecarrier 265. The height of substrate 263 above the bottom surface 266 ofsubstrate carrier 265 is established. Each slot establishes the positionof a substrate so that blade 263 may be inserted between substrateswithout touching them. A processing tool robot is generally calibratedto a standard substrate carrier so that substrates may be picked up ordropped off to any slot. Standard substrate carriers are used throughouta particular facility so that various tools are calibrated to a standardsubstrate carrier. Thus, substrates are repeatedly presented to a robotat the same positions and no recalibration is needed from one substratecarrier to another. Presenting a PCMD to a robot at one of thecalibrated positions allows the PCMD to be transferred as if it were astandard substrate. Incorporating an electronics module in a single unitwith a substrate carrier that presents a PCMD in this way provides aconvenient location to exchange data and to recharge the PCMD in anautomated fashion.

In some embodiments a HS is adapted for use with a substrate carrierother than cassette 204 such as a front opening unified port (FOUP) thusforming a handling system (or dock) where a PCMD may be stored,transported, charged and in which data may be exchanged. FIG. 8A showsan example of such a handling system 880. A FOUP is an industry standardcarrier for handling 300 mm wafers. The specifications of both the FOUPand of 300 mm wafers are set by industry standards established by SEMI.A FOUP is particularly suitable for use as part of a HS. It is designedto hold wafers and to be compatible with a wide range of semiconductorprocessing and metrology equipment. It protects the PCMD and provides aclean environment for it so that the PCMD does not pick up contaminationthat might be brought into a target environment. When handling system880 is placed at a loading station for a particular piece of equipment,the PCMD may be robotically transferred from the handling system to atarget environment such as a process chamber using the same robot thatis used for 300 mm wafers without requiring reconfiguration. Thus,handling of a PCMD may be identical with handling of a 300 mm wafer.Likewise, handling of handling system 880 may be identical to handlingof a FOUP. The PCMD measures and records the conditions in the targetenvironment during a specified period, for example, during a particularprocess recipe. Then, the PCMD is automatically returned to the handlingsystem 880. Transfer of handling system 880 from one piece of equipmentto another may also be automated. Thus, the combination of a PCMD andhandling system 880 allows a PCMD to be delivered to its destinationwith a little human intervention, little disturbance to the productionenvironment and minimal contamination to the target environment.

Inside handling system 880 an electronics module 808 similar toelectronics module 208 may be mounted. The electronics module 808contains a battery, an E-coil, and a data-receiving unit. A PCMD 800 maybe placed adjacent to the electronics module, in this example the PCMD800 is below the electronics module 808. In this position, it mayreceive RF power and RF data signals from the electronics module. It maytransmit data by LED to the electronics module 808.

Handling system 880 may also include optical readers to observe the PCMD100 and determine its rotational orientation. In the prior art wafersare rotated in a flat finder or notch finder to align them in a desiredrotational orientation. A flat finder usually rotates the wafer aboutits axis above a set of optical sensors that are directed at the edge ofthe wafer. These sensors detect the flat (or notch) of the wafer as itpasses and thus determine the rotational orientation. Subsequently,wafers may be realigned. Thus, relative motion between the wafer and thesensors is required. By using a greycode on a surface of a PCMD andhaving stationary optical readers, the rotational position of the wafermay be determined without any relative motion between the wafer and theoptical reader.

FIG. 8B shows a section of an edge of a PCMD 100 having greycode 850.Greycode provides a pattern that uniquely identifies locations at theedge of the wafer. Greycode is generally a code whereby successive wordschange by just one bit. On the wafer surface this is represented bychanges between light and dark areas created by patterning a depositedlayer. A word may be read along a radius such as A-A′ or B-B′. The wordread at A-A′ would be 1,1,1,0, and at B-B′ would be 1,0,1,1, where lightrepresents 1 and dark represents 0. This example uses a word of fourbits. Using a word of 8 or 9 bits allows better resolution because alarger number of uniquely identified locations are possible. Forexample, with 8 bits, 256 different uniquely identified locations arepossible. A reader, such as a linear array is used to determine theunique word at the location of the reader and also the position of theedge of the wafer. With two such readers, the rotational orientation ofthe wafer and the position of the center of the wafer may be found. Thegreycode may be located outside the area of the PCMD where the sensorsare located so that sensors do not impinge on the greycode area and thegreycode does not affect the sensors. Alternatively, where sensorsimpinge on the greycode area, the readers may be located so that atleast one reader will be able to read the greycode. For example, wheresensors are spaced 60 degrees apart near the edge of a PCMD, the readersmay be spaced 90 degrees apart so that if one reader is aligned with asensor then the other reader will have a clear reading. Both readersshould still read the position of the edge of the PCMD so that theposition of the center of the PCMD may be determined.

While rotation of a PCMD is not required to determine rotationalorientation where a greycode is used, movement of a PCMD may bedesirable for other reasons. Inductive coupling between PCMD 800 andelectronics module 808 improves as the distance between them decreases.Improved alignment between the position of the center of PCMD 800 andelectronics module 808 may also improve coupling. If the coupling isimproved, energy transfer is more rapid and the time to recharge PCMD800 may be reduced accordingly. Communication may also be improved whenPCMD 800 is correctly placed. Thus, moving PCMD 800 to the optimumposition relative to electronics module 808 may be of value. Rotation ofPCMD 800 may be desirable so that a particular rotational orientation ofPCMD 800 may be selected. Typically, maintaining the same orientationfrom one survey to another will be desirable. In this way, data from onesurvey may be accurately compared with data from another survey asindividual sensors collect data at the same locations each time. It maybe necessary to rotate PCMD 800 for alignment with process chamberelements such as positioning of specific PCMD sensors over heating zonesto correlate PCMD temperature profiles with heater zones. Sometimes, itis desirable to change the rotational orientation of a PCMD betweensurveys. A PCMD may have some inherent nonuniformity due to variationbetween individual sensors. Performing multiple surveys with differentPCMD orientations allows the effects of such nonuniformity to be reducedor eliminated. For example, a PCMD may perform surveys at a firstorientation, then at 90 degrees, 180 degrees and 270 degrees offset fromthe first orientation. The data from these surveys may then be averagedto provide a more accurate result.

FIG. 8C shows an alignment module 881 that can move a PCMD within ahandling system such as handling system 880. Alignment module 881includes a base structure 884 that forms a rigid platform for mountingother components. Base structure 884 is designed to fit in a slot withina handling system. For example, where handling system 880 is sized for300 mm silicon wafers, base structure 884 may be a disk with a diameterof approximately 300 mm. However, base structure may be thicker than asilicon wafer because it does not need to be moved in or out of a slot.Base structure 884 may be made of a strong, rigid material such as ametal or plastic.

A housing 887 is mounted to the upper surface of base structure 884.Extending from the upper surface of housing 887 are a rotation stage 883and an arm 888. Housing 887 may provide some support for rotation stage883 and arm 888 and also provides some containment for any particlesproduced by moving parts enclosed within housing 887.

Arm 888 is a movable part that can be retracted into housing 887 orextended so that it protrudes from housing 887. Arm 888 may be moved byan electric motor in response to a command signal from an electronicsmodule. At the end of arm 888 is a belt 882. Belt 882 passes around awheel or bearing so that it may rotate around the end of arm 888.Alternatively, a wheel alone may be used instead of belt 882. In anotherexample, instead of a pivoting arm such as arm 888, a post may be used.Such a post moves vertically with a wheel or belt extending from itsupper surface. Alternatively, PCMD 800 may be raised and supported bywheels around its perimeter. The wheels pushing up on the waferperimeter can raise PCMD 800 so it is floating above the FOUP orcassette ledge. By rotating the wheels, PCMD 800 can be centered bydriving it into the V-shaped slot and then retracting it back aspecified distance. PCMD 800 can then be rotated to the desiredrotational angle.

Rotation stage 883 is a disk that protrudes above the upper surface ofhousing 887. Rotation stage 883 may be rotated and may also be extendedin the vertical direction. Rotation is possible in both the raised andlowered position but is typically performed in the raised position.

A robot blade detector 886 is mounted to base structure 884. Robot bladedetector 886 may be an optical detector that can detect the presence ofan object in its field of view. Robot blade detector 886 is located sothat its field of view is placed where a robot blade from a host systemmay extend.

FIGS. 8D and 8E show alignment module 881 located within handling system880. Base structure 884 extends into a slot in handling system 880 tosupport alignment module 881. Base structure 884 may be fixed in thisposition to provide a stable platform. Electronics module 808 is locatedabove alignment module 881. PCMD 800 is between alignment module 881 andelectronics module 808. FIG. 8D shows PCMD 800 in its normal position.The edges of PCMD 800 are resting on shelves provided within handlingsystem 880. FIG. 8E shows PCMD 800 in a raised position. In thisposition it is closer to electronics module 808 so that coupling of RFpower between electronics module 808 and PCMD 800 is improved. PCMD 800is raised to this position by rotation stage 883.

FIGS. 8F-8H show alignment module 881 aligning PCMD 800. Each of FIGS.8F-8H shows two perspectives. The left view is from above and to oneside. The right view is a corresponding cross-sectional view. FIG. 8Fshows PCMD 800 positioned above alignment module 881. PCMD 800 is heldat its edges as in FIG. 8D. Arm 888 is retracted and is therefore notvisible in this view. Rotation stage 883 is clear of PCMD 800. PCMD 800may not be centered correctly at this point. This means that the centerof PCMD 800 may not be directly under the center of an electronicsmodule. Also, PCMD 800 may not have the desired rotational orientation.Either linear or rotational misalignment of PCMD 800 may be detected bygreycode readers as described above. In order to obtain an accurate mapof conditions measured by PCMD 800 the positions of the sensors on PCMD800 must be known. Thus, any map generated assumes a certain rotationalorientation. It is generally desirable that PCMD 800 be returned to thisorientation if any change occurs.

FIG. 8G shows arm 888 in the raised position. With arm 888 in thisposition, belt 882 contacts the underside of PCMD 800. Belt 882 engagesthe underside of PCMD 800 and drags PCMD 800 in the direction indicated.In a handling system this direction corresponds to dragging the PCMDdeeper into its slot. Therefore, the travel of PCMD 800 is limited bythe physical limits of the slot. Belt 882 may be a belt that is turnedby motor and that has a surface that provides sufficient traction todrag PCMD 800.

FIG. 8H shows alignment module 881 with arm 888 in the retractedposition (out of sight) and rotation stage 883 in a raised position.PCMD 800 is supported by rotation stage 883. PCMD 800 is clear of otherparts of the handling system at this point. PCMD 800 may be rotated byrotation stage 883 until it reaches a desired orientation. PCMD 800 mayremain in a raised-position for recharging from electronics module 808.When recharging is complete, rotation stage 883 may be lowered and PCMD800 may be returned to its normal position where it may be picked up bya robot blade that extends under it and lifts it from its slot.

Robot blade detector 886 ensures that alignment module 881 does notattempt to engage PCMD 800 while the robot blade is extended under PCMD800. If alignment module 881 tried to engage at such a time, damagecould occur to PCMD 800, alignment module 881 or the robot blade. Toprevent this alignment module 881 may have an interlocking mechanism toprevent it from operating when robot blade detector 886 detects thepresence of a robot blade.

After data is collected by a PCMD and transferred to a handling system,the data may still need to be transferred to a point where it can beaccessed by an end-user. This may be done in a variety of ways as shownin FIG. 9. For example, the end-user 985 may access the data collectedby PCMD 900 by using a laptop computer connected to the handling systemby a USB cable, IRDA connection Wi-Fi or Bluetooth wireless connection.The handling system 980 may connect to a network by an Ethernetconnection allowing the end-user to receive data on a PC at anotherlocation. A PDA may be used instead of a PC for receiving and viewingdata. Alternatively, the data may be recorded on a flash memory card andphysically moved to a laptop, pda or other device. A softwareapplication 987 processes the data sent by the handling system 980 toprovide data to end-user 985 in a format that is appropriate. Forexample, digital data may be converted into temperature readings.Software application 987 may run on a variety of platforms includinglaptop PC, desktop PC or PDA.

In one embodiment, the transfer of data from handling system 980 isachieved by using an active RFID transmitter in handling system 980.This takes advantage of the presence of an RFID reader close to the FOUPto transmit data to a network where it may be accessed by an end-user.Semiconductor Fabrication facilities (Fabs) that use FOUPs generallytrack the individual FOUPs and their contents by means of RFID tags.Tags are generally passive devices capable of providing anidentification number when they are interrogated by a reader. A readeris generally provided at the load port where a FOUP connects to aprocessing system so that the identity of the FOUP at the load port atany particular time is known. A network of such readers throughout theFab are connected to a software system that can monitor the position ofdifferent FOUPS and coordinate the movement of FOUPs to optimizeefficiency. Certain industry standards regarding such a network aredetailed in “General model for communications and control ofmanufacturing equipment,” (GEM), SEMI E30 and SEMI E87-0703. Thepresence of such a reader connected to a network provides a convenientway to transfer data from a handling system to an end-user.

An active RFID transmitter may be used to send recorded data and otherinformation from a handling system to a reader. The network may beconfigured to process data in packets corresponding in size to theidentification number for a FOUP, typically 80 bytes. In this case, theinformation from handling system may need to be sent in a series of 80byte chunks. Using an RFID system for this purpose has the advantagethat the receiving hardware already exists at the desired location andis connected to a network, the transmission is over a very short rangeand thus requires very little power and does not generally suffer frominterference from neighboring systems. Two types of RFID are commonlyused, a low frequency system at a frequency of 125 kHz that has a rangeof less than 12 inches and a high frequency system operating at 13.56MHz that has a range of about 90 feet. Either may be used for sendingdata according to this invention. Active RFID transmitters may transmitin 3-dimensions so that the alignment of the transmitter and reader arenot critical. One example of such a transmitter is an ECM electronics3DC1515. While the above example refers to FOUP technology used with 300mm wafers, this aspect of the invention may also be used with otherindustry standard substrates and substrate carriers such as 200 mmwafers and SMIF (standard mechanical interface). Similar industrystandards exist for other substrates and carrier.

FIG. 2B shows the front or user side of HS 200. A memory card 228 isshown inserted into electronics module 208 and may be considered part ofHS 200. HS 200 accommodates any number of memory card formats such asbut not limited to the smartcard®, Sony memory stick®, the SecureDigital (“SD”) card®, Compact Flash (“CF”), or Multi-Media Card®(“MMC”). A PCMD is sent out “on a survey” to record the variousconditions in different types of environments. For each environment andfor the entire survey, it may be desirable to alter various parametersof the PCMD such as the sampling rate, sampling duration, and thesensors used. Display 232 quickly conveys information to a userregarding the setup of the PCMD such as the number and arrangement ofsensors to be used in a survey, the length and times of the variouscycles of a survey, and the sampling rate of the sensors and sensorelectronics etc. A survey profile and the data retrieved on the surveymay also be stored on the memory card 228 or within flash memory ofelectronics module 208.

All the parameters of PCMD 100 and HS 200 may also be accessed andconfigured by a personal computer or other smart device thatcommunicates via a universal serial bus (USB) of port 224 or via aninfrared port 220. They may also be accessed by a remote controlcommunicating to infrared port 220. HS 200 and the PCMDs may also beconfigured and the data gathered may be manipulated with the functionswitches 240 that are software driven and control/access the most oftenused parameters of a PCMD. Indicator lamps 232 also serve to inform theuser of the condition of HS 200 and the PCMDs within HS 200. Viewport244 allows a user to view one or more of the PCMDs.

FIGS. 3A and 3B are cross sections of embodiments of PCMD 100 (withoutthe components) that will be referenced by the flowcharts of FIGS. 4Aand 4B, respectively. The cross sections and flow charts describing howthe PCMDs are made should be viewed in tandem.

FIG. 4A describes the process of making an embodiment with a singleconductive layer used for the circuit traces. In step 404 of FIG. 4A,insulating layer 304 is formed upon substrate 102. Insulating layer 304preferably comprises an oxide, but may be any well known insulatingmaterial, and may be deposited or grown upon the surface of substrate102. In step 408, insulating layer 308 is formed upon insulating layer304. Insulating layer 304 and 308 preferably, but not necessarily,comprise different materials. In the preferred embodiment, insulatinglayer 308 comprises a nitride. In step 412, a conductive layer 312 isformed upon insulating layer 308. Next, in step 416, electrical tracesare patterned and etched in conductive layer 312 according to well knownpatterning and etching methods. In step 420, passivation layer 316 isformed upon the conductive traces of step 416. In step 424, cavities 142for components 140 are formed within the substrate through one or moreof the layers. The cavities 142 may be mechanically formed or may beetched. In step 428, components 140 (not shown) are inserted withincavities 142 and electrically coupled to the traces in conductive layer312, seen in FIG. 1C. Next, in step 432, a passivation layer (not shown)is formed over components 140 and the other layers. The passivationlayer may comprise any well-known materials, but preferably comprisespolyimide or oxynitride. Optionally, step 436 may be performed, in whichan electrical and chemical protective shield layer is formed over thepassivation layer. This is especially useful in protecting the PCMD fromvery harsh processing environments such as in plasma etch chambers, asthe shield layer is nearly impermeable to the gases and other elementscommon to such environments. The shield layer should also be resistantto the etching process induced by high energy ion bombardment in plasmachambers. One example of a shield layer is actually a composite ofdifferent layers, including a polymer layer such as Mylar®, a PE layer,a metallic foil, and a sealant layer such as surlyn®. The totalthickness of the shield layer may range from 25 to greater than 99microns.

FIG. 4B describes the process of making an embodiment with twoconductive layers coupled by inter-level vias. Steps 404 and 408 are thesame as those in FIG. 4A. In step 412, the first conductive layer 312Ais formed on insulating layer 304. In step 413, a dielectric layer 310is formed upon conductive layer 312A. After that, openings for vias 312Care formed in dielectric layer 310 instep 414. Next, instep 415,conductive layer 312B and vias 312C are formed on/in the dielectriclayer 310. In step 416 electrical traces are patterned and etched in theexposed portion of conductive layers 312A and 312B. Steps 420-436 arethe same as in FIG. 4A.

FIGS. 10A and 101B show examples of lids 1010-1013 protecting components1020-1022 of the PCMD from the environment. In FIG. 10A a single lid isused for three components. The number of components covered by a singlelid depends on the sizes and locations of the components but may beanything from one component to all the components in the PCMD. FIG. 10Ashows three components 1020-1022 and the attached wire bonds 1048covered by a single lid 1010. In FIG. 101B separate lids 1011-1013 areused for each component 1020-1022. Various materials may be used to formlids such as lids 1010-1013. For example, a ceramic lid similar to thatused for packaging integrated circuits may be adapted to cover acomponent or group of components in a PCMD. For particularly harshchemical environments lids may be made from materials such as sapphirethat resist chemical attack. Where protection from electromagneticfields is required, lids may be made of conductive material such asmetal or doped silicon. For some applications, plastic lids may be used.Lids 1010-1013 are bonded to the substrate 1002 in a conventionalmanner.

In the example of FIG. 10C, a single lid 1030 is used to cover the uppersurface of the substrate 1002. Lid 1030 may be made of the same materialas substrate 1002. For example, where the substrate is made of silicon,the lid may also be made of silicon. Thus, PCMD 1000 resembles a siliconwafer from the outside. Its appearance and characteristics are similarto those of a silicon wafer so that the measured values are as close aspossible to the values that would be found in a silicon wafer. The lid1030 may be bonded to substrate 1002 to form a sealed unit. Cavitieswithin such a unit may be filled with a suitable material to exclude gasthat might expand at high temperature and cause the unit to fail.

In the example shown in FIG. 10D, a three layer structure is used.Traces (not shown) may be formed and components 1020-1022 may attachedto substrate 1002 and bonded to the traces. Then, a second layer 1050 isput in place. This layer has cutouts formed for the components1020-1022. This layer may be silicon so that it has similarcharacteristics to the substrate 1002. Next, a lid 1030 is attached tothe upper surface of layer 1050. This method allows cavities to beuniform in depth because the depth of each cavity is equal to thethickness of layer 1050. Also, the upper and lower surfaces of layer1050 may be highly planar providing good attachment to substrate 1002and lid 1030.

In an alternative embodiment, instead of raising PCMD 800 to move itcloser to the electronics module, the electronics module or a portion ofthe electronics module is lowered to bring it closer to PCMD 800. FIG.8I shows a portion of an electronics module that contains E-coil 810being lowered towards PCMD 800. As the distance between E-coil 810 andPCMD 800 decreases, the efficiency of power transfer from E-coil 810 toPCMD 800 improves. Typically, when E-coil is close to PCMD 800, the timeto recharge PCMD 800 is about ten minutes.

When robot blade detector 886 detects a robot blade approaching PCMD800, moving parts that might interfere with the robot blade must beplaced in positions where they do not interfere. Where E-coil 810 islowered to improve coupling with PCMD 800, it must be retracted beforethe robot blade attempts to lift PCMD 800. Typically, this means that itmust be retracted within 0.1-0.3 seconds from the time that a robotblade is detected by robot blade detector 886.

In one embodiment, the position of the FOUP door may determine theposition of E-coil 810. When the FOUP door is open, the robot mayattempt to pick up a PCMD, so E-coil 810 is kept in the raised position.When the FOUP door is closed, the robot will not attempt to pick up thePCMD, so E-coil 810 is placed in the lowered position. The movement ofE-coil 810 may be triggered or powered by the movement of the FOUP door.Alternatively, the movement may be powered by a motor or a spring.Linking E-coil motion to the FOUP door motion may make robot bladedetector 886 unnecessary.

A compression algorithm is utilized for the multiple channels of data.The algorithm may use both spatial and temporal compression. It issuitable for signals with small temporal motion and uses an adaptivecompression that depends upon signal shape and environment. It comprisesthree steps: 1) analyzes spatial temperature distribution; 2) analyzestemporal distribution; 3) analyzes temperature profile andcharacteristics; and 4) compresses or omits certain data based upondifferences across the wafer detected in the above steps.

The embodiments described above have applications in monitoringprocessing conditions in locations other than processing chambers.Conditions experienced by wafers during transport and storage may alsoaffect the characteristics of the devices produced and therefore it maybe desirable to measure and record such conditions. For example, a PCMDmay remain in a FOUP to record conditions in the FOUP. This data may berecorded in the PCMD or may be transmitted by RFID without being stored.

While particular embodiments of the present invention and theiradvantages have been shown and described, it should be understood thatvarious changes, substitutions, and alterations can be made thereinwithout departing from the spirit and scope of the invention as definedby the appended claims. For example, the location and type of thesensors may be different than in the examples described.

1. A sensing apparatus for sensing conditions in target environments ina processing facility where a standard substrate is transported in astandard substrate carrier that establishes a position of the standardsubstrate relative to a surface of the standard substrate carrier andwhere the robot of at least one processing tool is calibrated to theposition of the standard substrate relative to the surface of thestandard substrate carrier, comprising: a first portion that includes: asubstrate; a plurality of sensors attached to the substrate; a secondportion that includes: a substrate carrier that establishes the positionof the first portion relative to a surface of the substrate carrier tobe the same as the position of the standard substrate relative to thesurface of the standard substrate carrier; an electronics module thatcommunicates with the first portion, the electronics module attached tothe substrate carrier; and wherein the first portion may be movedindependently of the second portion.
 2. The sensing apparatus of claim 1wherein the substrate carrier is a standard substrate carrier.
 3. Thesensing apparatus of claim 1 wherein the position of the standardsubstrate relative to the surface of the standard substrate is thevertical height of the standard substrate above the bottom surface ofthe standard substrate carrier.
 4. The sensing apparatus of claim 1further comprising: a receiving unit attached to the substrate thatreceives power from the electronics module; and a transmitting unit inthe electronic module that transmits power to the receiving unit.
 5. Thesensing apparatus of claim 4 wherein the receiving unit is located atthe center of the substrate so that when the substrate is placed in thesubstrate carrier the receiving unit is aligned with the transmittingunit regardless of the rotational orientation of the substrate.
 6. Thesensing apparatus of claim 4 wherein the receiving unit receives datafrom the electronics module and the transmitting unit transmits data tothe receiving unit.
 7. The sensing apparatus of claim 4 wherein thetransmitting unit comprises an E-coil and the receiving unit comprises aconductive coil and a magnetic conductive layer.
 8. The sensingapparatus of claim 1 wherein the second portion further comprises anRFID transceiver electrically connected to the electronics module sothat data may be sent from the electronics module to the RFIDtransceiver and data may be sent from the RFID transceiver to anexternal receiver.
 9. The sensing apparatus of claim 1 furthercomprising: a pattern on at least one surface of the substrate; and anoptical reading apparatus attached to the substrate carrier that readsthe greycode pattern on the substrate to determine the orientation ofthe substrate.
 10. The sensing apparatus of claim 1 wherein the secondportion further comprises an alignment module that aligns the firstportion relative to the substrate carrier.
 11. A sensing apparatus forsensing process conditions in a processing tool that has a robot thattransfers a standard substrate between a standard substrate carrier anda process chamber, comprising: a process condition measuring device,comprising: a substrate; a plurality of sensors attached to thesubstrate; a handling system, comprising: a substrate carrier that holdsthe process condition measuring device, the robot transferring theprocess condition measuring device between the substrate carrier and theprocess chamber; and an electronics module attached to the substratecarrier that communicates with the process condition measuring devicewhile the substrate carrier holds the process condition measuringdevice.
 12. The sensing apparatus of claim 11 wherein the substratecarrier is a standard substrate carrier.
 13. The sensing apparatus ofclaim 1 wherein the substrate carrier is a front opening unified pod(FOUP).
 14. The sensing apparatus of claim 11 wherein the substratecarrier is a wafer cassette.
 15. The sensing apparatus of claim 11wherein the process condition measuring device further includes at leastone battery and other components attached to the substrate and thelocation of the at least one battery and the other components that areattached to the substrate are configured such that the center of gravityof the substrate with the at least one battery and the other componentsis the same as the center of gravity of the substrate alone.
 16. Thesensing apparatus of claim 11 wherein the process condition measuringdevice further includes conductive traces connecting sensors to a CPU,at least one battery, a clock crystal and an RF inductive coil.
 17. Aprocess condition measuring device for measuring conditions in a targetenvironment, comprising: a substrate; a plurality of sensors attached tothe substrate; and a plurality of components located on the surface ofthe substrate or within cavities formed in the surface of the substratesuch that the balance of the substrate with the plurality of sensors andthe plurality of components is the same as the balance of the substratealone when the substrate spins about a central axis.
 18. The processcondition measuring device of claim 17 wherein the center of gravity ofthe process condition measuring device is along a central axis of theprocess condition measuring device, the central axis passingperpendicularly through the center of the surface of the substrate. 19.The process condition measuring device of claim 17 wherein the targetenvironment is a process chamber that processes substrates havingpredetermined physical dimensions and the physical dimensions of theprocess condition measuring device are the same as the predeterminedphysical dimensions.
 20. The process condition measuring device of claim17 wherein the plurality of components includes two or more batteriesthat are located equidistant from the central axis and at opposite sidesof the central axis.
 21. The process condition measuring device of claim17 further comprising an energy receiving device comprising an RFinduction coil overlying an RF return pad located at the center of thesubstrate.
 22. The process condition measuring device of claim 17further comprising a plurality of data transmitting devices thattransmit data from the process condition measuring device.
 23. Theprocess condition measuring device of claim 22 wherein the datatransmitting devices are LEDS at different locations and whereinindividual ones of the plurality of LEDs may be separately enabled ordisabled.
 24. The process condition measuring device of claim 17 furthercomprising a CPU that is mounted to the substrate and is individuallycovered by a prefabricated lid.
 25. The process condition measuringdevice of claim 24 further comprising a memory IC and a clock crystaland wherein the CPU, the memory IC and the clock crystal areindividually covered by prefabricated lids.
 26. The process conditionmeasuring device of claim 17 further comprising a single prefabricatedlid that covers most or all of a surface of the substrate and covers aplurality of components mounted on the surface or mounted withinindividual cavities within the surface.
 27. The process conditionmeasuring device of claim 26 wherein the lid is composed of the samematerial as the substrate.
 28. The process condition measuring device ofclaim 17 further comprising a crystal oscillator circuit, the circuithaving a temperature compensation feature that modifies a bias voltagewithin the crystal oscillator circuit to compensate for temperaturechanges.
 29. A method of surveying conditions in a target environmentcomprising: robotically moving a process condition measuring device froma substrate carrier to a target environment; acquiring data in thetarget environment and recording the data in the process conditionmeasuring device; robotically returning the process condition measuringdevice to the substrate carrier; transferring the data from the processcondition measuring device to an electronics module attached to thesubstrate carrier while the process condition measuring device is in thesubstrate carrier.
 30. The method of claim 29 further comprisingtransferring energy from the electronics module to the process conditionmeasuring device and storing the energy within the process conditionmeasuring device.
 31. The method of claim 29 further comprising sendingthe data from the electronics module attached to the substrate carrierto a receiver that is not attached to the substrate carrier.
 32. Themethod of claim 29 wherein the substrate carrier is a cassette.
 33. Themethod of claim 29 wherein the substrate carrier is a front openingunified pod (FOUP).
 34. The method of claim 29 wherein transferring thedata from the process condition measuring device to an electronicsmodule is by light from an LED, the LED being selected from a pluralityof LEDs in the process condition measuring device according to a routinethat selects the optimum LED.
 35. The method of claim 29 wherein theprocess condition measuring device comprises a plurality of electricalcomponents having specified operating temperature ranges and the processconditioning measuring device experiences a high temperature m thetarget environment that is outside the specified operating temperaturerange of at least one of the plurality of electrical components, theprocess condition measuring device having temperature compensationcircuitry to allow the process condition measuring device to operate atthe high temperature.
 36. The method of claim 29 wherein the processcondition measuring device is spun at high speed in the targetenvironment.
 37. The method of claim 29 further comprising determiningthe position of the process condition measuring device in the substratecarrier.
 38. The method of claim 29 further comprising moving theprocess condition measuring device in the substrate carrier.
 39. Themethod of claim 29 further comprising changing the rotationalorientation of the process condition measuring device in the substratecarrier.
 40. The method of claim 29 further comprising moving a portionof the electronics module while the process condition measuring deviceis in the substrate carrier.
 41. A method of making a process conditionmeasuring device that may collect data and may record or transmit thedata for subsequent use comprising: depositing a conductive layer on asubstrate; patterning the conductive layer to form a plurality oftraces; forming a plurality of cavities in the substrate; placing aplurality of electrical components in the plurality of cavities, theplurality of components including at least one sensor and at least onebattery; connecting individual ones of the plurality of electricalcomponents to one or more of the plurality of traces; and depositing apassivation layer over the traces and components.
 42. The method ofclaim 41 further comprising forming a shield layer over the passivationlayer.
 43. The method of claim 42 wherein the shield layer is comprisedof a composite of different layers.
 44. The method of claim 41 furthercomprising forming a second conductive layer and patterning the secondconductive layer to form a second plurality of traces.